/******************************************************************************
 * Copyright (c) 1999, Carl Anderson
 *
 * this code is based in part on the earlier work of Frank Warmerdam
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 ******************************************************************************
 *
 * shpcentrd.c  - compute XY centroid for complex shapes
 *			and create a new SHPT_PT file of then
 * 			specifically undo compound objects but not complex ones
 */

/* the centroid is defined as
 *
 *      Cx = sum (x dArea ) / Total Area
 *  and
 *      Cy = sum (y dArea ) / Total Area
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "shapefil.h"
#include "shpgeo.h"

int main( int argc, char ** argv ) {
    if( argc < 3 )
    {
	printf( "shpcentrd shp_file new_shp_file\n" );
        return 1;
    }

    DBFHandle old_DBF = DBFOpen(argv[1], "rb");
    if (old_DBF == NULL) {
	printf("Unable to DBFOpen old files:%s\n", argv[1]);
	return 1;
    }

    SHPHandle old_SHP = SHPOpen(argv[1], "rb");
    if (old_SHP == NULL) {
	printf("Unable to SHPOpen old files:%s\n", argv[1]);
        DBFClose(old_DBF);
	return 1;
    }

    int nEntities;
    int nShapeType;
    SHPGetInfo( old_SHP, &nEntities, &nShapeType, NULL, NULL );

    DBFHandle new_DBF = DBFCloneEmpty (old_DBF, argv[2]);
    if (new_DBF == NULL) {
	printf("Unable to create dbf for new files:%s\n", argv[2]);
        DBFClose(old_DBF);
        SHPClose(old_SHP);
	return 1;
    }

    SHPHandle new_SHP = SHPCreate ( argv[2], SHPT_POINT );
    if (new_SHP == NULL ) {
	printf("Unable to create new files:%s\n", argv[2]);
        DBFClose(old_DBF);
        SHPClose(old_SHP);
        DBFClose(new_DBF);
	return 1;
    }

    char *DBFRow = (char *) malloc ( (old_DBF->nRecordLength) + 15 );

    int byRing = 1;
    for( int i = 0; i < nEntities; i++ )
    {
        SHPObject *psCShape = SHPReadObject( old_SHP, i );

        if ( byRing == 1 ) {
          for ( int ring = 0; ring < psCShape->nParts; ring ++ ) {
	    SHPObject *psO = SHPClone ( psCShape, ring,  ring + 1 );

            PT Centrd = SHPCentrd_2d ( psO );

            SHPObject *cent_pt;
            cent_pt = SHPCreateSimpleObject ( SHPT_POINT, 1,
        	(double*) &(Centrd.x), (double*) &(Centrd.y), NULL );

            SHPWriteObject ( new_SHP, -1, cent_pt );

            memcpy ( DBFRow, DBFReadTuple ( old_DBF, i ),
		 old_DBF->nRecordLength );
            DBFWriteTuple ( new_DBF, new_DBF->nRecords, DBFRow );

            SHPDestroyObject ( cent_pt );

	    SHPDestroyObject ( psO );
          }
        } else {
          PT Centrd = SHPCentrd_2d ( psCShape );

          SHPObject *cent_pt = SHPCreateSimpleObject ( SHPT_POINT, 1,
        	(double*) &(Centrd.x), (double*) &(Centrd.y), NULL );

          SHPWriteObject ( new_SHP, -1, cent_pt );

          memcpy ( DBFRow, DBFReadTuple ( old_DBF, i ),
		 old_DBF->nRecordLength );
          DBFWriteTuple ( new_DBF, new_DBF->nRecords, DBFRow );

          SHPDestroyObject ( cent_pt );
        }
    }

    printf ("\n");

    DBFClose(old_DBF);
    SHPClose(old_SHP);

    DBFClose(new_DBF);
    SHPClose(new_SHP);

    return EXIT_SUCCESS;
}
